Changes in psychometric functions on two out of three auditory tasks during adolescence

Adolescents continue to develop on some psychoacoustic tasks, but most studies use adaptive tracking procedures to estimate thresholds; therefore, the effect of prolonged maturation on psychometric functions is relatively unknown. Here, we tested adolescents (age 10–18) and young adults (age 19–23) on three conditions: temporal interval discrimination (100 ms standard), gap detection in bandpass noise, and frequency discrimination (1000 Hz standard). Performance was measured using the method of constant stimuli and a 3AFC task. Data were analyzed by measuring threshold (66.7% correct; proxy for sensitivity), the slope of the psychometric function (a proxy for internal noise), and the proportion of listeners who met criteria for outliers (more than 2 SD from the mean), had poorly fit psychometric functions, or were unable to complete the task. Preliminary results suggest that temporal interval discrimination thresholds, slopes, and proportion of excluded data did not change with age. Gap detection thresholds improved and slopes became steeper with development, and the proportion of excluded data decreased with increasing age. Frequency discrimination thresholds did not improve with age, but slopes became steeper and excluded data decreased with maturation. These data suggest that internal noise may be decreasing during adolescence, even when thresholds stay the same. [Funded by NIDCD.]